Burglar-alarm.



No. 710,746. Patented Oct. 7, I902. B. A. BRACHVOGEL.

BURGLAH ALARM.

(Application filed Jan. 11, 1902.]

(No Model.)

UNTTni) STATES PATENT OFFICE.

ROBERT ADAM BRACHVOGEIJ, OF CHICAGO, ILLINOIS.

BURGLAR-ALARM.

SPECIFICATION forming part of Letters Patent No. 710,746, dated October 7, 1902.

Application filed January 11, 1902. Serial No. 89,317- (No model.)

To all whom zit may concern:

Be it known that 1, ROBERT ADAM BnAcH- VOGEL, a citizen of the United States, residing in the city of Chicago, county of Cook,

and State of Illinois, have invented anew and useful Improvement in Burglar-Alarms, of which the following is a specification.

My invention relates to burglar-alarms automatically set off by the opening of the window whereto the alarm is adjusted; and the objects of my invention are, first, to provide a clamp whereby the alarm may be secured to a window-sash; second, to provide means for detachably attaching said clamp to the alarm in order that said clamp may be removed from the alarm during shipment or when applied to objects for which the clamp is not required, and, third, to provide means for limiting the travel of the controlling-rod. I attain these objects by the mechanism illustrated in the accompanying drawings, in which Figure 1 is a side view showing the alarm adjusted to window-sashes. Fig. 2 is a view of the alarm looking in the direction of the arrow, Fig. 1. Fig. 3 is a face View of the device, showing the bell removed for the purpose of exposing the interior mechanism. Fig. 4 is a face view of the chief members of the releasing mechanism. Fig. 5 is a rear view with the casing removed, showing the mainspring. Fig. 6 is a transverse sectional view taken on the line (3 6, Fig. 3, looking in the direction of the arrows. Fig. 7 is a top view, and Fig. 8 is a side view, of the detachable clamp for-fastening the alarm to a windew-sash.

Similar reference characters denote similar parts throughout the several views.

1 represents the central plate, whereto the framework of the device is attached and whereon the gears and moving parts are mounted. Extending transversely through said plate 1 and revolubly mounted therein is the main arbor 2, which is fixed at one extremity to the mainspring 3 and at the opposite extremity is threaded to screw into the alarm-bell 4. The extremity of the mainspring opposite to the arbor 2 is fixed to the supplemental spring box or casing 5, wherein said spring is inclosed. By means of the sleeve 6, freely encircling the main arbor 2, the said spring-casing 5 is rigidly connected to the main gear-wheel 7. The plate 8 constitutes a part of the gear-frame, being rigidly secured to the central plate 1. Between said plate 8 and the main or first gear-Wheel 7 is a ratchet 9, rigidly secured to the arbor 2 and detained by the pawl 10, pivoted to the frameplate 8. When the bell 4 has been screwed tight upon the threaded extremity of the arbor 2, if the frame-plates 1 and 8 are held stationary the further rotation of said bell causes the said arbor 2 to be rotated in the frame of the device, and said arbor is prevented from rotating backward on account. of the operation ofsaid ratchet and pawl. Now the main gear-wheel 7, sleeve 6, and easing 5 rotate as a single piece, and as the gear-wheel '7 is prevented from escaping by certain devices attached to the vmain frame and hereinafter described it follows that the rotating of the arbor 2 winds up the mainspring 3 in the casing 5. In other words, when the main gear 7 is held fixed in the main frame, and since the casing 5 and gear 7 are rigidly connected, and also since the mainspring is connected at one end to the said arbor and at the other to said casing 5,

it follows that the rotation of the arbor 2 Q will wind up the mainspring, so that the easing will tend to rotate so as to unwind said spring when the gear 7 is permitted to rotate in the main frame. The escapement mechanism whereby said gear 7 is controllably permitted to rotate in the main framewill now be described.

The escapement wheel 11 is revolubly mounted upon a suitable .arbor in the main frame and is normally'detained by means of the pallets 12 12 upon the escapement-lever 13. Said wheel 11 is connected bya train of gearing 14c 14 with the wheel 7, and the mainspring 3 therefor tends to drive said escapement-wheel 11. The hammer 15 is connected to the lever 13 by the arm 16, and the parts are so related that when the pivoted lever 13 is not detained the force of the escapementwheel 11, acting upon the pallets 12 12, will drive said lever so as to rock upon the pivot thereof and -permit the intermittent revolution or escapement of said wheel 11. The

rocking or vibration of said lever 13 causes the hammer to make a series of strokes upon the bell 4, thereby sounding an alarm.

The device for preventing the vibration of the lever 13 consists of a slotted detent 17, having a tongue 18, adapted to engage said lever. A pin 19 penetrates through said detent 1.7 into the plate 1 and forms a guide for permitting a limited travel of said detent. By means of the spring 20, acting upon the detent 17, said detent is normally held so as to engage and prevent the vibration of the lever 13. Near one extremity said detent has an arm 21, which is secured to the controlling-rod 22. Then said rod forces the detent 17 away from the lever 13, said lever is released and permits the escapement of the wheel 11.

Inclosing the spring 3, casing 5, and adjacent parts is the lower casing 23, which is dish-shaped and attached at its periphery to the central plate 1 by means of the tongues 24 on said casing, which enter the notches 25 on said plate. The controlling-rod 22 projects a considerable distance beyond the easing 23 and is preferably pointed at its outer extremity, as shown, for better sinking into the wood of the window whereto the device is to be adjusted. An arm 26 is attached to the lower casing 23 and has a turned-up portion 27, apertured in such a manner as to form an arm for said rod 22. Said arm 26 is also provided with the sharpened prongs 28 on the opposite side of the lower casing for sinking into and engaging exterior parts in the event that the clamping device be not employed. As the prongs 28 are secured to the main frame of the device and the rod 22 is secured to the detent 17, which is movable therein, it follows that the movementof said rod relatively to said arm 26 operates said detent 17, and thereby controls the operation of the device. I have found in practice, however, that when great force was applied to the rod 22 to force it into the casing, as is frequently the case when the presence of the alarm is unsuspected, the arm 21 would be broken off. In order to prevent such breakage, I have formed a collar 29 upon the rod 22 just outside of the turned-up portion 27 in such a position that when said rod is forced into the casing a sufficient distance to release the alarm said collar 29 comes to a stop against said turned-up portion 27, thereby relieving said arm 21 of the strain. In order to further strengthen the rod 22, I have supplied a brace 30, extending from the arm 26 and encircling said rod.

In order to insure the security of position of the alarm when attached to a window-casing, I have provided a detachable clamp 31,

provided with the pendent extremities 32 and 33. The extremity 32 is adapted to engage the lower window-sash 34, while the outer extremity 33 carries the set-screw 35. The loop 36 is rigidly secured to the lower extremity of the arm 26 and is provided atits extremities with the jaws 37 and 38, as best shown in Fig. 2. Said loop 36 is made of comparatively thin metal, so as to be somewhat resilient, and the clamp 31 is detachably secured to the jaws 37 and 38 of said loop by means of the cars 39 and 40, respectively.

My invention is applied and used in the following manner: 'When it is desired to call attention to the unauthorized opening of a window, the clamp 31 is secured to the lower sash by means of the set screw 35. The alarm is then attached to said clamp by placing the jaw 37 beneath the car 39 and subsequently springing the jaw 38 beneath the ear 40. The point of the rod 22 is caused to engage the upper sash 41, but in a loose manner, so that the rod is projected and the detent 17 prevents the vibration of the hammer 15. hen the device is adjusted in this manner, as illustrated in Fig. 1, it is evident that either the attempted raising of the lower sash or lowering of the upper sash will cause said rod to be forced into the framework of the device, thereby causing the sounding of the alarm.

hat I claim as new, and desire to secure by Letters Patent, is-

1. In a burglar-alarm, the combination of a bell, a pulsative device acting upon said bell, a framework inclosingsaid pulsative device, a rod for controlling said pulsative de vice, an arm extending beyond said framework, a turned-up portion at the extremity of said arm for guiding and bracing said rod, a collar on said rod for contacting said turnednp portion of said arm to thereby limit the travel of said controlling-rod, a brace on said arm between the bell and the outer extremity of the arm for receiving the controlling-rod to brace the same, and a detachable clamp on said framework for attaching said alarm in operative position.

2. In an alarm of the class described, the combination of a pulsative device, a framework inclosing the same, a controlling-rod adapted to engage one of two relatively movable objects, a loop secured to said framework, jaws upon said loop,a clamp fol-securing said framework to a windowsash, and ears on said clamp for detachable engagement by the jaws of said loop.

ROBERT ADAM BRAOIIVOGEL.

\Vitnesses:

ARTHUR M. Cox, SADIE WOLF. 

